Typically, when a president wants to make policy, he has to negotiate a deal with Congress. Because that hasn’t worked out for President Donald Trump in securing his border wall, he’s tried to find another way to lock down the $5 billion he wants to build it. “I have the absolute right to do national emergency if I want,” he told reporters on Wednesday. By Thursday night, administration officials were reportedly looking at reallocating funds earmarked for national-disaster relief in Texas and Puerto Rico, which were hit by hurricanes last year.

In making this move, Trump would explicitly attempt to circumvent the political process. But he would also be exploiting a long-standing fact about the U.S. government: Executive power has expanded, with Congress’s blessing, to the point that unilateral action like this may in fact be perfectly legal. Democrats are apparently looking into the possibility of a court challenge if Trump moves forward, but they may be banking on an uncertain legal stopgap. Ultimately, the impasse over the alleged national emergency at the border reveals the extent to which the American government now runs on executive authority, and how heavily legislators have come to depend on the courts to referee their political disagreements.

National emergencies, as Americans know them today, are an artifact of another era of expansive executive power. As allegations from the Watergate scandal were closing in on President Richard Nixon, he began declaring national emergencies in response to everything from a postal strike to a trade imbalance, says Kim Lane Scheppele, a professor at the Woodrow Wilson School of Public and International Affairs at Princeton University. Congress sought to regulate this presidential power, which had also been used liberally by prior presidents, with its 1976 National Emergencies Act.

But as Elizabeth Goitein recently wrote in The Atlantic, this law still left presidents with extensive power and little accountability. So-called emergencies have been left in place “for years on end” without congressional oversight; the president is required to do little to justify any action he takes. Trump’s possible use of the national-emergency mechanism might be novel, but “the national-emergency system has been ripe for abuse for a long time, and has been gently misused for decades,” Goitein told me. “The conversation is long overdue.”

In other words: The most remarkable thing about Trump’s national-emergency solution to the border-wall impasse is not that he is breaking laws, but that he’s working within them. “It’s the first time that he’s actually done something that looks like he talked to a lawyer first,” Scheppele said. “Trump is actually, weirdly, coloring within the lines Congress drew. And that’s an improvement over what he usually does.”

Democrats will likely sue Trump in court if he does in fact declare a national emergency. Legal scholars have debated who would win in that scenario, but “the strategy [Trump is reportedly] proposing,” of using a national emergency to reallocate previously apportioned funds, “is pretty legally sophisticated,” Scheppele said. Under the statute, the president has latitude to determine what a national emergency is, according to a new report from the Congressional Research Service, and courts have typically deferred to presidential judgment in this area.

In many ways, the reason this situation has escalated to this point is because of Congress’s inability to govern. Over time, lawmakers have increasingly relied on the executive branch—to which it has granted expansive power—to make policy. This is arguably both a cause and an effect of partisan tribalization, which also led to this deadlock: In recent weeks, Republicans have intentionally blocked efforts to reopen the government. In the past decade, despite many tries, legislators haven’t been able to pass comprehensive immigration reform.

In the absence of a functioning legislature, Democrats have become increasingly reliant on courts to fight Trump on everything from the ban on immigrants and refugees from predominantly Muslim countries to the proposed removal of transgender military service members. Their success has been mixed. “Everybody wants the law to provide the answer. But the answer here is a political answer,” Scheppele said. “The judges are not that likely to say no here.”

Still, there is the question of facts. Trump’s lawyers may have developed a successful technique for putting the border-wall policy in place, but if they are not acting in good faith, their actions could be damaging in the long run.

“The problem here is that virtually everyone, probably including the president himself, knows that there’s no evidence of any emergency,” says Marty Lederman, a former deputy assistant attorney general in the Justice Department and a visiting associate professor at Georgetown University. Attempted illegal crossings over the southern border are down. Almost all known or suspected terrorists who are apprehended attempting to enter the country are caught in airports or at sea. Perhaps most importantly, the situation at the border doesn’t fit any plain-language definition of an “emergency”: It’s neither new, nor unanticipated, nor particularly fast-moving. In order to function, America’s legal system depends on lawyers, legislators, and judges to operate in the same fact-based universe. As that gets eroded, so does the power of the law.

Trump often acts as a mirror for the American political system, reflecting back its vulnerabilities and excesses. Other presidents, including President Barack Obama, have been accused of massively expanding executive power. But certain checks “kept things from going really bonkers,” says Heidi Kitrosser, a law professor at the University of Minnesota: “norms of relatively responsible behavior, norms of some modicum of fact-finding, etc.”

Without those in place, the U.S. political system is remarkably fragile. And that’s what Trump has revealed. “The seeds of this problem are multifold, and they’ve been in the ground for quite a while,” Kitrosser says. “With the Trump presidency, we’re primed for them to really come to fruition.”

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Emma Green is a staff writer at ​The Atlantic, where she covers politics, policy, and religion.